1. Field of the Invention
The present invention relates to a foam generating apparatus for bathing and a foam bath system using the same.
2. Related Background Art
There have been proposed lots of foam generating applauses for foam bathing.
Japanese Patent Application Unexamined Publication No. 60-90523 (Document 1) discloses a new foam bathing method using soap foam that is filled in a bathtub. According to the disclosure thereof, the new foam bathing method allows the amount of water and heat required for foam bathing to be reduced, compared with conventional foam bathing methods. A foam generating apparatus disclosed in Document 1 stores a hot aqueous soap solution as an undiluted solution and blows air into the aqueous soap solution and stirs to generate foam, which is fed into the bathtub.
Japanese Utility-Model Application Unexamined Publication No. 01-59481 (Document 2) discloses a foam bathing apparatus similar to that of Document 1. The foam bathing apparatus of Document 2 has a foam bath room which can accommodate a user and is provided with a shower capsule equipped with a shower nozzle. In addition, a soap solution tank is arranged to communicate with the foam bath room and is provided with a porous plate at the bottom thereof. By supplying air to the soap solution tank from the rear surface side of the porous plate, foams are generated in the soap solution tank and then the shower capsule is filled with foam to allow the user to enjoy foam bathing.
Japanese Utility-Model Application Unexamined Publication No. 03-892 (Document 3) discloses a foam bathing apparatus equipped with a bathtub, an undiluted solution tank for generating foam, which is separated from the bathtub, an air blow-in nozzle through which air is blown into the undiluted solution tank for generating foam, and a lead pipe for leading foams generated in the undiluted solution tank into the bathtub. Document 3 describes that a large number of small holes are dispersedly arranged at the air blow-in nozzle. FIGS. 2 through 6 of Document 3 illustrate air blow-in nozzles having various different profiles and how small holes are formed.
Japanese Patent Application Unexamined Publication No. 10-137153 (Document 4) discloses a foam generating device for foam bathing. It is a small device having simple structure and adapted to generate cleansing foam by using foaming stones.
Japanese Patent Application Unexamined Publication No. 2000-83851 (Document 5) discloses a bath system for foam bathing. As illustrated in FIG. 4 of Document 5, a foam generating apparatus uses a porous bottom plate to generate foam by blowing air into the porous plate like that of Document 4.
Japanese Patent Application Laid-Open Publication No. 2002-78628 (Document 6) discloses a foam generating apparatus for bathing, which is equipped with a nozzle having a plurality of air-jet holes formed and a container for containing detergent solution for generating foam in the inside. According to the disclosure of Document 6, the air-jet holes of the nozzle are arranged dispersedly at horizontal locations of the container and the cross sectional area of each of the air-jet holes is preferably not smaller than 7.85xc3x9710xe2x88x923 mm2 and not greater than 7.85xc3x9710xe2x88x921 mm2, forming bathing foam made of same-size bubbles.
However, the above-described conventional foam generating apparatuses have the following disadvantages.
First of all, Document 1 does not practically describe anything about the specific structure of the foam generating apparatus. It only describes that air is blown into aqueous soap solution and the solution is stirred. Therefore, Document 1 teaches only common knowledge about foam generating means.
Document 2 describes the structure of a foam generating apparatus such that the soap solution tank is provided with the porous plate at the bottom thereof and air is supplied from the rear surface side of the porous plate. However, with the arrangement disclosed in Document 2, air is supplied to the soap solution tank from below, thereby generating foam made of relatively thick bubbles showing relatively large and not-uniform diameters, which is so-called foam having a high moisture content (wet foam) and therefore not preferable for foam bathing. Similarly, the bath system disclosed in Document 5 is not preferable for foam bathing because foams are generated by blowing air into the foam-generating porous plate from below.
The foam generating device for bathing disclosed in Document 4 is intended to be used as toy. It is difficult to generate uniformly sized foams that are suitable for foam bathing by means of a foaming stone having small holes whose diameters vary widely. Additionally, Document 4 does not teach specifically anything about the type of foaming stone to be used for foam bathing and the size of the small holes.
The foam bathing apparatus disclosed in Document 3 and the bath system disclosed in Document 6 are both characterized by the positional arrangement of small holes in an air blow-in nozzle, allowing the amount of foam generated in the container to be uniform. However, it is difficult to generate less moistened uniform foam with a thin liquid film (dry foam) suitable for foam bathing in a short period of time by such an arrangement that small holes are dispersedly formed by way of a mechanical process in the container.
It is an object of the present invention to provide a foam generating apparatus capable of solving the above-described problems. Some specific objects of the present invention are as follows:
to provide a foam generating apparatus and a foam bath system that can generate dry foam made of uniformly-sized bubbles suitable for foam bathing;
to provide a foam generating apparatus and a foam bath system that use a relatively simple and moderately prices device to generate a large volume of bathing foam in a short period of time; and
to provide a practical foam bath system and a foam generating apparatus suitable for the foam bath system, which are combined with a foam fining device to generate a large amount of finer mousse-like foam in a short period of time, that makes the bathing person comfortably feel as if he or she were in warm water.
The other objects of the invention and means for solving the problems will become apparent from the remaining part of the disclosure.
While the present invention has a number of aspects, it will be described below in terms of its major aspects.
According to a first aspect of the present invention, a foam generating apparatus for foam bathing includes: a foam generation device for generating initial foam by jetting air into a foaming agent solution; and a foam fining device for fining the initial foam to produce the foam for foam bathing. The foam generation device includes: a foaming chamber storing the foaming agent solution on a bottom wall thereof; and a foaming tool provided within the foaming chamber, for jetting air from an opening to the bottom wall of the foaming chamber, wherein the opening is provided at an end of the foaming tool and faces the bottom wall, wherein the opening is covered with a net having an opening ratio between 27.7% and 49.5% and a number of air-jet openings per unit area between 9690/cm2 and 24800/cm2.
According to a second aspect of the present invention, the opening provided at the end of the foaming tool is covered with a net having a mesh number between 250 mesh and 400 mesh.
According to a third aspect of the present invention, a foam bath system includes: a foam generation device for generating initial foam by jetting air into a foaming agent solution; a foam fining device for fining the initial foam to produce finer foam; and a foam container for containing the finer foam for foam bathing. The foam fining device includes a predetermined number of nets through which the initial foam is fined into the finer foam, the nets having a mesh number between 120 mesh and 250 mesh, wherein the nets are placed at intervals of a distance 30-100 times as long as a mesh size of the nets, wherein the predetermined number of the nets is one selected from 3 to 10.
According to a third aspect of the present invention, an above-described number of nets of the above-described mesh range are arranged at intervals as described above to allow warm foam to be made fine and uniform. Such an arrangement allows a large amount of fine and uniform warm foam to be generated in a short time, achieving good foam bathing as if a user soaked in hot water bath.
The foam generation apparatus according to the first aspect of the present invention may have such a structure that a foaming chamber may be provided with a foam outlet opening which is elongated in a longitudinal direction along a side of a bathtub, wherein a plurality of foaming tools are arranged at predetermined intervals along the longitudinal direction of the foam outlet opening.
Preferably, the foam generation apparatus according to the first aspect of the present invention is provided with a foaming chamber which has a foam outlet opening which is placed at a position higher than a liquid surface of the foaming agent solution by 20-300 mm.
It is preferable that the foam generation apparatus according to the first aspect of the present invention is further provided with a temperature raising reservoir for storing an amount of foaming agent solution required for at least one time, wherein the temperature raising reservoir comprises a heating device for adjusting a temperature of the foaming agent solution stored in the temperature raising reservoir, wherein the foaming agent solution is supplied from the temperature raising reservoir to the foam generation device.
In the foam bath system according to the third aspect of the present invention, the foam fining device is preferably provided with four to five nets through which initial foam c an be made finer.
In addition, the nets may have a mesh number between 150 mesh and 200 mesh.
In the foam bath system according to the third aspect of the present invention, the foam container may be shaped like a bathtub, wherein the foam fining device has a foam outlet opening through which the finer foam is supplied to the bathtub, wherein the foam outlet opening is elongated in a longitudinal direction of the bathtub and provided at a position near a bottom wall of the bathtub in each side wall of the bathtub, wherein the foam generation device and the foam fining device are attached to the bathtub.
Further, a volume ratio of water content in the finer foam to gas in bubbles of the finer foam at 40xc2x0 C. is preferably set within a range between 1:50 and 1:200.
Furthermore, an average diameter of bubbles of the finer foam is preferably set within a range between 0.2 mm and 2 mm.
Still further, liquid soap is preferably used as a foam generating agent of the foaming agent solution, wherein a weight ratio of the liquid soap to water is between 3:97 and 10:90.
In the foam bath system according to the third aspect of the present invention, a pressure on the first layer of the nets provided in the foam fining device in operation may be between 2.2 kPa and 2.7 kPa.
In the third aspect of the present invention, the form generation device may be modified. For example, the form generation device may be provided with at least one of a nozzle, an orifice, and a air-scattering plate.
Hereinafter, the present invention will be described in detail.
For the purpose of the present invention, xe2x80x9cfoaming agent solutionxe2x80x9d refers to liquid from which foam is generated. The most commonly used foaming agent solution may contain water and a foam generating agent. The foaming agent solution may also contain a certain solvent in addition to water so as to make foam. It is preferable that the solvent is friendly to the human body.
When water is used, soap for cleaning bodies such as liquid body soap or solid soap may be used as a foam generating agent.
A solution obtained by dissolving liquid soap into water may be easily prepared and suitably used as a foaming agent solution.
The mesh and material of a net used in the foaming tool and the foam fining device are not particularly limited in the present invention. The mesh may be formed like a lattice, a rhombic or a tortoise shell. The net is preferably made of metal.
In general, in order to generate foam that is a mass of bubbles in gaseous-liquid phase, it is necessary to make the internal pressure of a bubble higher than the atmospheric pressure by blowing gas into liquid. The smaller the size of a bubble, the greater the necessary internal pressure thereof. However, since the internal pressure is balancing with the surface tension of the liquid film of a produced bubble, the pressure applied to the body of a bathing person is much smaller than that of hot water in a bathtub and substantially equal to the atmospheric pressure. In addition, since the density of foam is low, the bathing person feel less resistance when moving the body in the foam, lighting the load on the heart-lung system of the bathing person.
Foam generated in gas-liquid phase is a mass of bubbles each having gas or air enveloped with a thin film of liquid. The inventors of the present invention consider the properties of foam to embody the present invention, which will be described below. It should be noted that the properties 2-7 were discovered by the present inventors.
Property 1 of Foam: When foam is warmer than the room temperature, the temperature of the surface layers of the foam falls in a short time because of evaporation.
Property 2 of Foam: In a mass of foam, a liquid component of the foam moves downward due to the gravity. Accordingly, when the foam is hot, a temperature difference is developed in the inside such that the upper part of the mass becomes cold while the lower part of the mass becomes hot. Additionally, when the liquid component is separated, the separated liquid makes the body of the bathing person feel hot because it has a heat capacity of liquid. This phenomenon becomes remarkable as the liquid content of foam is larger (and hence the liquid film is thicker) and the concentration of soap is smaller.
Property 3 of Foam: Once foam has been generated at a certain temperature, it is highly difficult to control the temperature of the foam because the temperature of the foam does not rise or fall in a short time except for the instances of the above properties 1 and 2.
Property 4 of Foam: The real volume of liquid is small relative to the apparent volume of foam. Therefore, the heat capacity of a mass of foam is much smaller than hot water having the same volume. In other words, a mass of foam needs to show a temperature level that is much higher than hot bathing water when it needs to provide a feeling of warmness. However, since the temperature level can vary depending on the fineness of foam, the temperature of liquid film, the air temperature within the foam and so on, it is necessary to carefully select the temperatures of foam-generating gas and the foaming agent solution depending on a foam generating method.
Property 5 of Foam: Finer foam having a smaller diameter makes the bathing person feel more comfortable and the temperature thereof falls slowly. To the contrary, rough foam makes the bathing person feel uncomfortable and the temperature thereof falls quickly. Additionally, fine foams are apt to coalesce with each other and can easily disappear, compared with rough foams.
Property 6 of Foam: Although foam can be conveyed by using some other medium or by generating foam continuously to push previously generated foam, it is very difficult, unlike gas and liquid, to equally branch foam on the way of movement or to form a number of branches of the foam at the end of the way of movement, to which the foam is equally distributed.
Property 7 of Foam: Although a foaming agent solution generates foam well when the concentration of a foam generating agent contained in the foaming agent solution is high, an increase of generated foam is not in proportion to an increase in the concentration of the foam generating agent. Foam is generally turned back into liquid immediately after the generation. When the concentration of the foam generating agent is too low, this tendency of going back to liquid becomes remarkable, so that an extremely small amount of foam is generated and the generated foam disappears immediately into liquid. Therefore an optimal concentration of the foam generating agent most suitable for a foam generating method needs to be selected.
For the purpose of generating foam suitable for foam bathing, conventional foam generating apparatuses including those disclosed in Documents 3 and 6 are adapted to generate foam by using a pipe-shaped nozzle having air-jet openings that are formed by way of a mechanical process. Additionally, in the case of Document 6, nozzles are arranged horizontally while air-jet openings are made to face upward (see FIG. 1 of Document 6). Furthermore, the nozzles are arranged deep in the foaming agent solution and the distance from the air-jet openings of the nozzles to the surface of foaming agent solution is about three to four times greater than the diameter of the nozzles.
In the case of Document 3, on the other hand, pipes that operate as nozzles are separated by a spacing S so that generated foams may rise straight upward smoothly without being obstructed (see FIGS. 2 and 3 of Document 3). Furthermore, in the case of both Document 3 and Document 6, the foam generating apparatus is designed with emphasis on distributing the positions of the air-jet openings of the nozzles so that foams may be generated uniformly over the entire bottom wall of the foam generating apparatus. In Document 3, for example, all the arrangements illustrated in FIGS. 2 through 6 are intended to distribute small holes uniformly over the entire bottom area of the container of the foam generating apparatus. In Document 6, the disclosed foam generating apparatus is also characterized significantly in that the air-jet openings of the nozzles are distributed horizontally.
However, from a detailed analysis of experiments repeatedly conducted by the inventors of the present invention, it was found that dry foam having substantially uniform diameter can be generated within a short time by arranging a net having very small jet openings with facing the bottom wall of the foam generating apparatus to jet out air to areas around the net, rather than by distributing the air-jet openings of nozzles as the conventional cases.
More specifically, the inventors conducted research on a foaming tool operating as a nozzle for generating foam and finally found that the nozzle of the foaming tool should be formed by a net having densely disposed air-jet openings (mesh) such that generated foam can be distributed substantially evenly over a large area of the bottom wall of an internal foam generating chamber within the foam generation device.
The inventors further found that a large volume of foam suitable for foam bathing can be generated preferably by reducing the distance between the bottom wall surface and the net operating as air-jet openings so as to raise the pressure between the bottom wall and the net and disperse foam generated from the mesh of the net through the very narrow spacing in all directions and more preferably by the foaming tool composed of a pipe body extending vertically with facing the bottom wall of the internal foam generating chamber.
Furthermore, the inventors thought of functionally dividing the foam generating apparatus into a foam generation device for initially generating foam and a foam fining device for making the generated hot foam finer. More specifically, the inventors tried to fine the foam generated by the foam generation device by forcing it to pass through a plurality of nets. As a result, it was found that generation of foam that makes the bathing person comfortable is greatly affected by conditions such as the mesh size, the number of the nets, and spacing between nets. Then, by carefully studying parameters including the mesh size, the number of nets and the spacing between nets, the inventors successfully realized a foam bath system that can generate a large amount of fine mousse-like foam to the extent of filling the bathtub in a short period of time.
It should be noted here that the temperature of foam suitable for xe2x80x9cfoam bathingxe2x80x9d can vary depending on various conditions, for example, the feeling of the user, who may wish to bath with foam at relatively high or low temperature, the above-described properties of foam (Property 4 of Foam in particular), the distance over which generated foam travels to the foam containing means that may typically be a bathtub, and the ambient temperature.
According to a first aspect of the present invention, the net has a relatively large opening ratio per unit area, 27.7%-49.5%. Therefore, a relatively low-pressure air source can be employed, reducing in total cost of the foam bath system and its running cost. Further, the net is used to realize air-jet openings. Accordingly, compared with the conventional method of mechanically boring the air-jet openings, an increased amount of air can be supplied and thereby a large amount of foam can be supplied to a bathtub in a short time. In addition, the number of air-jet openings per unit area is 9690/cm2-24800/cm2 and therefore a large number of minute air-jet openings are arranged at high density. Such an arrangement is used in the foam generation device, allowing generation of relatively small and uniform foam. Furthermore, a foam fining device is provided to make the small and uniform foam finer, which can supply a large volume of fine foam suitable for foam bathing.
According to a second aspect of the present invention, the net of 250-400 mesh is used, wherein xe2x80x9cmeshxe2x80x9d is the unit of size represented as the number of openings per linear inch. Assuming square-shaped openings of the net, the size of each opening of the net of 250-400 mesh is 33.4- to 71.5-square-xcexcm, which provides a relatively large opening ratio per unit area. Therefore, a relatively low-pressure air source can be employed, reducing in total cost of the foam bath system and its running cost. Further, the net is used to realize air-jet openings. Accordingly, compared with the conventional method of mechanically boring the air-jet openings, an increased amount of air can be supplied and thereby a large amount of foam can be supplied to a bathtub in a short time. In addition, by using the net of 250-400 mesh, a large number of minute air-jet openings can be arranged at high density, allowing generation of relatively small and uniform foam. Furthermore, a foam fining device is provided to make the small and uniform foam finer, which can supply a large volume of fine foam suitable for foam bathing.
According to a third aspect of the present invention, an above-described number of nets of the above-described mesh range are arranged at intervals as described above to allow warm foam to be made fine and uniform. Such an arrangement allows a large amount of fine and uniform warm foam to be generated in a short time, achieving good foam bathing as if a user soaked in hot water bath.